Hovendal C, Bech K, Gottrup F, Andersen D
Scand J Gastroenterol Suppl. 1984;89:19-22.
The purpose of this study was to elucidate the effect of alpha-, beta- and dopaminergic receptor stimulation and blockade on pentagastrin and bethanechol stimulated gastric acid secretion in conscious dogs with gastric fistula. Gastric acid secretion was found to be subject to a dose related inhibition by isoprenaline. The dose of isoprenaline producing approximately 50% inhibition was higher in the bethanechol--than the pentagastrin experiments (0.10 vs. 0.03 micrograms/kg/min.) and slightly lower after parietal cell vagotomy. The antisecretory effect was mediated via the beta 1-receptors alone. The inhibitory effect of isoprenaline on pentagastrin stimulated acid secretion showed the characteristics of competitive type and on bethanechol stimulated acid secretion of non competitive type. An increasing and dose-dependent stimulation of bethanechol stimulated gastric acid secretion was found for dopamine 1, 5 and 10 micrograms/kg/min. Dopamine (40 micrograms/kg/min.) exerted an inhibitory effect on pentagastrin and bethanechol stimulated gastric acid secretion mediated, via the beta 1-receptors. The stimulatory effect of low doses of dopamine during bethanechol stimulation could not be defined as an effect via beta-receptors. This dual response, the weak inhibitory effects and the potent decreasing effect on antral gastric motility indicate that dopamine has no physiologic relevant effect on gastric acid secretion. One may conclude that beta 1- and beta 2-receptors may exert an influence on gastric acid secretion in dogs. The main effect of dopamine seems to be on gastric motility, while the effect on gastric acid secretion is of minor importance.
本研究的目的是阐明α-、β-和多巴胺能受体的刺激与阻断对有意识的胃瘘犬在五肽胃泌素和氨甲酰甲胆碱刺激下胃酸分泌的影响。发现异丙肾上腺素对胃酸分泌有剂量相关的抑制作用。在氨甲酰甲胆碱实验中，产生约50%抑制作用的异丙肾上腺素剂量高于五肽胃泌素实验（0.10对0.03微克/千克/分钟），在壁细胞迷走神经切断术后略低。抗分泌作用仅通过β1受体介导。异丙肾上腺素对五肽胃泌素刺激的胃酸分泌的抑制作用表现为竞争性类型，对氨甲酰甲胆碱刺激的胃酸分泌的抑制作用表现为非竞争性类型。发现多巴胺以1、5和10微克/千克/分钟的剂量对氨甲酰甲胆碱刺激的胃酸分泌有增强且剂量依赖性的刺激作用。多巴胺（40微克/千克/分钟）对五肽胃泌素和氨甲酰甲胆碱刺激的胃酸分泌有抑制作用，通过β1受体介导。在氨甲酰甲胆碱刺激期间低剂量多巴胺的刺激作用不能被定义为通过β受体的作用。这种双重反应、微弱的抑制作用以及对胃窦部胃动力的显著降低作用表明多巴胺对胃酸分泌没有生理相关作用。可以得出结论，β1和β2受体可能对犬的胃酸分泌有影响。多巴胺的主要作用似乎在于胃动力，而对胃酸分泌的作用次要。
